August: Radar pcbs

A radar pcb usually contains two antennas that are incorporated in the circuit pattern as etched copper structure. One of them is the transmitter and the other the receiver of radar waves. A radio-frequency circuit generates the waves and analyses the reflected signal. The entire function of the RF circuitry is based on special base materials that are capable of transmitting this radio-frequency radiation to the antenna with as little damping as possible and radiate it. The RF signals are analysed by a digital circuit located in modern radar sensors frequently on the back of the pcb. The front of the pcb contains the complete RF part of the circuit, including the antenna structure.

What is the definition of a radar pcb?

Radar pcbs are electronic circuits that are capable of producing and receiving radio frequency signals. They are based on special RF base materials. The entire circuit generates a so-called radar lobe, which is sent by the antenna structure of the pcb, then reflected by objects and received again by the antenna structure of the pcb.

In what applications are radar pcbs used?

Radar pcbs are often encountered in automotive applications. More and more, radar applications are also used in the industrial sector and in building automation, such as in level meters, track monitoring or for automated door openers.

What is the concrete function of radar pcbs?

Radar pcbs are used for the detection of speeds, measurement of distances and detection of objects. In the automotive sector, there are two different frequency bands. In close-range applications of typically up to 30 m, frequencies around 24 GHz are used, while in long-range applications of up to 200 m, frequencies range from 77 to 79 GHz.

What functions are performed by radar pcbs especially in the automotive sector?

In the automotive sector, radar pcbs are used in a wide range of applications, such as, among other things, adaptive cruise control, autonomous emergency braking, collision mitigation, stop-and-go assistant, lane change assistant, lane departure warning system, blind spot detection, cross traffic alert, rear parking aid, and a few more. In the future, the use of several radar sensors will become the standard in vehicles with fully or even only partially automated driving. The higher the degree of automation, the higher the number of radar sensors required.

Why is SCHWEIZER well prepared for the challenges of radar pcbs?

For modern radar systems, currently so-called hybrid assemblies are often being used. This is understood as a combination of FR4 and RF base materials. Due to their special transmission properties of radar signals, RF base materials are five to ten times more expensive than FR4 base materials and show clearly different processing properties. Thanks to its more than ten years of experience in radar applications, SCHWEIZER masters the challenges of these material combinations. For example, the specifications for warping and twisting the pcb present a much greater problem than with standard FR4 pcbs. Moreover, the low tolerances of the conductor track and antenna geometries are often near the limit of the options available with modern pcb processes. SCHWEIZER has optimised the entire process chain with a view to the applications described, making radar pcbs nowadays a core competence of SCHWEIZER. SCHWEIZER is world market leader in the segment of automotive radar pcbs. In addition, with WUS SCHWEIZER has a very well experienced and good cooperation partner in Asia in order to provide the necessary capacity for the strong market growth.

Why are radar pcbs much more complicated to manufacture in the frequency range 77-79 GHz compared with the 24 GHz range?

Owing to their wavelength, which is approximately two thirds lower, antenna structures and conductor geometries must be designed correspondingly smaller and manufactured within significantly narrower tolerance limits. At the same time, teflon-based base materials are often used, which are more difficult to process not only due to the high hardness of the fillers, but also due to their clearly lower stability. The reliability requirements of the end products increase driven by their usage in safety-critical areas. Since an increasing number of sensors must do with less and less space, the integration density of the circuit in combination with high power losses increases as well. Here SCHWEIZER's embedding technologies reveal ways for future system solutions.

Why is long-standing experience in the manufacture of radar pcbs a great advantage for a pcb manufacturer?

The use of special RF base materials in conjunction with standard FR4 base materials and their highly advanced processing requires many years of development and experience in high-volume manufacture of these products. Our customers value this experience and integrate SCHWEIZER into the development process early on, in order to substantially shorten the development period and start volume production using stable production processes.